The present invention relates generally to clamping apparatus and, more particularly, to clamping apparatus for transmitting a traction force to a metallic workpiece, such as in connection with the repair of automobile bodies, for deforming the metallic workpiece.
Clamping apparatus adapted to be attached to metallic workpieces for the purpose of transmitting traction forces to such workpieces are, of course, well known. For example, in connection with repairing the bodies of automobiles which have been involved in collisions or other accidents, clamping apparatus have been utilized which are fixed to the dented area of the automobile body for the purpose of transmitting a traction force applied by a pulling bridle to that body area for the purpose of straightening or deforming the same to its original configuration.
However, such conventional clamping apparatus are not entirely satisfactory for several reasons. More particularly, in general, conventional clamping apparatus of the type described above can transmit traction forces in only a single direction at any one time. Thus, should it be required during the repair operation on an automobile body to change the direction of the traction force, it is necessary to detach the clamping apparatus and reaffix the same in a new more appropriate orientation with respect to the body. Further, even recognizing that a conventional clamping apparatus can be detached and reaffixed to the body to vary the direction of the traction force, such clamping apparatus still generally do not provide an unlimited choice for the pulling or traction forces. Thus, most of the prior art clamping apparatus of this type provide only a single direction in which the traction force can be applied to the workpiece, namely in the direction of the clamping angle of the jaws.
Although clamping apparatus are known wherein the traction force can be applied at right angles to the clamping jaws as well as in the direction thereof, such a limited choice for the direction of the traction force is still not sufficient to provide a capability of repairing the damaged automobile body without the necessity of several detachment and reaffixing operations. Thus, conventional clamping apparatus of this type still cannot transmit a traction force in the precise desired direction, should the latter be other than in the direction of or at right angles to the clamping jaw.